1. Field of the Invention
The present invention relates to a method of and an apparatus for retrieving images and a method of and an apparatus for managing images, capable of efficiently retrieving desired dynamic images from dynamic images generated in a short period of time.
2. Related Background Art
As a method of retrieving desired dynamic images from those dynamic images which have been stored in advance, there is a method for retrieving the desired dynamic images according to classification codes and associated information such as positional data of all dynamic images which are stored for each title of dynamic images and a method for visually retrieving the dynamic images by a user while actually feeding the dynamic images at a high speed by the user or directly retrieving the dynamic images at a specified interval while observing frame sequences.
As a method for retrieving the dynamic images by using the images to be retrieved, one frame of images to be retrieved has been entered and a frame corresponding to the frame image entered has been selected from all frames for actual retrieval.
However, in a method of retrieving the dynamic images according to the above-described classification code such as positional data, the user should store the positional data in connection with each title of the dynamic image; for example, even though the user has wanted to know the data at a position on a video tape where the desired title is stored, the dynamic image could not be retrieved if there were no clue except the video tape.
In a method of visually retrieving the dynamic images in rapid feeding, there has been a problem that, though this method can be executed if the number of dynamic images stored is small, a time required for retrieval would be longer and therefore the method would be unpractical if a number of dynamic images are stored.
In a method of retrieving dynamic images by using images to be retrieved, it is necessary to determine whether a frame image entered is identical to a frame image of dynamic images.
Though pattern matching is available as a practical method of retrieval, there has been a problem that pattern matching for retrieval requires a lot of time.
As another method, a histogram of images and characteristics amount matching for determining whether the image includes special information (for example, character A) are available for retrieval. However, it is necessary to calculate in advance the characteristics amount for each frame as a whole at the time storage of images and a lot of time is required for such calculation.
In other words, in case of retrieval by using the characteristics of the image, for example, an attribute value information as xe2x80x9ccharacter xe2x80x9cAxe2x80x9d is included in the imagexe2x80x9d, such attribute value information should be given to the storage process and the information should be manually entered to ensure accurate and minute entry of information and therefore a lot of time has been required and it has been practically impossible to carry out such input operation, depending on the number of subject frames. Lately, studies as to automatic extraction of the attribute value information in accordance with the contents of images have been conducted (xe2x80x9cImage Retrieval Adapted for Subjective Similarityxe2x80x9d the treatise magazine of the Information Processing Society, Vol. 31, No. 2, pp. 227-236 and others). The information extracted from images has been controlled and stored as array values at the characteristics amount level. However, the above-described automatic extraction also includes a problem in the aspect of accuracy.
In this case, therefore, a difference in level exists between the attribute value information and the characteristics amount information to be provided for retrieval and another art to compensate for this difference is required for obtaining a proper accuracy.
An object of the present invention is to provide a method of and an apparatus for retrieving dynamic images and a method of and an apparatus for managing images capable of solving the above-described problems.
Another object of the present invention is to provide a method of and an apparatus for retrieving dynamic images and a method of and an apparatus for managing images capable of efficiently retrieving dynamic images in a short period of time.
A further another object of the present invention is to provide a method of and an apparatus for retrieving dynamic images by which a dynamic image is used as a search key.
A preferred embodiment of the present invention to attain the above-described objects is a method of retrieving dynamic images corresponding to dynamic images entered for retrieval from dynamic images of a database, comprising a first extraction step for extracting a characteristics amount in accordance with a scene change of a dynamic image of the database; a second extraction step for extracting a characteristics amount in accordance with a scene change from the dynamic image entered for retrieval; and a determination step for determining a dynamic image corresponding to the dynamic image entered for retrieval, which is included in the dynamic images of the database, from said characteristics amounts extracted by the first extraction step and said second extraction step.
A further another object of the present invention is to provide a method and an apparatus for retrieving dynamic images and a method of and an apparatus for managing images capable of retrieving in a short period of time and saving manpower wherever possible.
A further another object of the present invention is to provide a method and an apparatus for retrieving dynamic images and a method of and an apparatus for managing images which have novel functions.